


in for the kill

by vulpixie



Category: Voltron: Legendary Defender
Genre: Alpha/Beta/Omega Dynamics, First Time, M/M, Mating Cycles/In Heat, Rimming, just dirty pwp, nothing to see here folks, very brief mention of mpreg
Language: English
Status: Completed
Published: 2016-08-07
Updated: 2016-08-07
Packaged: 2018-07-27 16:25:24
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,622
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/7625578
Author URL: https://archiveofourown.org/users/vulpixie/pseuds/vulpixie
Summary: <blockquote class="userstuff">
              <p><br/>It’s not that he hadn’t known Keith was an omega. It’s just – never been terribly relevant until now.</p>
            </blockquote>





	in for the kill

**Author's Note:**

> keith is 19, shiro is 22 or so. this is completely self-indulgent dirty porn ¯\\_(ツ)_/¯

 

 

 

Five minutes past dinner call, and Keith still hasn’t shown.

“Well, when’s the last anyone heard from him?” asks Allura, tucking a stray curl behind a pointed ear.

“I saw him in the training room earlier, but that was hours ago,” Pidge offers.

Shiro frowns. It’s not like Keith to skip out on a meal. Normally, he’s the first to arrive and the first to finish, wolfing down his share like he’s got somewhere to be. Shiro doesn’t like to linger on the idea, but he probably knows the heavy pang of an empty stomach too well to pass up free food.

Hunk looks concerned, too. “Maybe he’s not feeling well?”

Finishing his bowl and setting down his spoon, Shiro reassures them. “I’m sure everything’s fine, but I’ll check on him.”

The vast sprawl of the castle means that he has time to think on his way to the sleeping quarters. If Keith really _is_ sick, it’s good that he’s taking time to rest instead of pushing himself until he collapses like last time. Still, not eating is only going to make him feel worse. Unless he’s throwing up, that is – what if he has some kind of stomach bug?

It occurs to him that Keith being ill is actually pretty unlikely, considering that the only people they’ve come in contact with are each other, and the rest of them aren’t sick. He hopes there isn’t some kind of weird alien space flu that infects humans.

Stopping short of Keith’s door, he shakes himself out of his thoughts. He’s being ridiculous. Keith probably just got caught up in training; maybe he’s not even in his room. He knocks anyways, as a precaution.

“Go _away,_ ” comes a muffled voice from inside, and Shiro’s eyebrows raise. It hardly even sounds like Keith.

Clearing his throat, he raises his voice. “Keith, it’s me. You okay in there?”

There’s an abrupt _thud_ of feet hitting the floor, then an increase in volume as they stride towards him. The doors slide open with a mechanic hum, and there stands Keith, looking – well. A once-over would be too brief to register all of the visual information Keith’s presented him with, so Shiro takes his time. The loose strands of hair that have escaped Keith’s ponytail is plastered to his face with perspiration, which has also gathered to stain the collar of his t-shirt. The only other scrap of clothing on his body is a pair of loose-fitting boxers, slung low on his hips. Shiro drags his eyes back up to his face, which is also beaded with sweat and high in color. But what really catches his attention is that _–_ _scent_.

Keith is in heat, Shiro’s brain informs him clinically, but he thinks the immediate rush of blood to his dick has impaired his cognitive function, because the thought is far off and hazy. He’s caught traces of omegas in heat before, but mostly from afar, and besides that, they’d smelled nothing like this. It’s sort of like ginger, but _not_ , just – indescribable and overwhelming and so potent that he has to clench his fist until nails dig into his palm keep from reaching out.

“Shiro,” Keith breathes, lips parted and red like he’s been biting them, and, well. _Fuck._

It’s not that he hadn’t known Keith was an omega. It’s just – never been terribly relevant until now. He’d noticed it immediately when they first met: a different smell, fainter, but still distinctly giving away Keith’s sexual status. It was something he tried to ignore, though, because it didn’t matter. It _doesn’t_ matter. Shiro may be an alpha, he may be so viscerally drawn to Keith that it feels like a punch to the gut sometimes, but it’s not going to happen. Not even now, when he can already tell by the look on Keith’s face that he’s going to ask him, _beg_ him.

“I – I thought you were on suppressants,” Shiro manages, his voice gravelly and low to his own ears, and he clears his throat self-consciously.

Keith’s eyes are dark and searing, pinning him to the spot. “Yeah, well. I ran out.”

They’re lucky that Pidge hasn’t presented yet and Lance and Hunk are betas, because Keith is going to be out of commission for at least a week, and there sure as hell aren’t any pharmacies in deep space, Shiro reflects distantly. They’d better hope the Galra don’t decide to knock on their door. Shaking himself from his thoughts and intentionally breathing through his mouth, he takes a step back. “I’m gonna go get you some food and water, and I’ll tell everyone to leave you alone –”

Keith’s hand darts out and hauls him into the room by the front of his vest before he can blink. “Don’t go,” he pleads, voice hoarse and desperate. The doors hiss shut behind them.

Shiro sets his jaw and turns his head to the side, Keith’s face suddenly way too close for comfort. “You aren’t – thinking straight right now.”

“Then I never am,” Keith retorts. “Don’t pretend you don’t know how long I’ve wanted this.”

He’s not wrong; they’ve been dancing around this since Shiro was still a cadet. There’s always been a reason why he just _can’t_. No matter how Keith’s eyes linger. No matter how infuriatingly stubborn and difficult and beautiful he is. No matter how much Shiro wants to collect each tentative, genuine smile Keith cracks and tuck it away for a rainy day.

Shiro takes a deep breath to steady himself. “We – we can’t compromise the team like this. I have to lead, I can’t afford to play favorites –” He bites back a groan as Keith slides his hands up his chest, tightening on his pecs.

“I’m not asking you to. Not out in the field, at least.” Keith’s overheated body is pressed up against him from head to toe now, which is honestly just playing dirty.

Even as his arms wrap around Keith seemingly of their own accord, he makes a last ditch effort. “There aren’t any condoms,” he hedges. He’s not just stalling, it’s a real concern. Shiro loves Keith to death, truly, (and _there’s_ a thought he doesn’t want to examine too closely) but he would be a shit parent.

Keith seems to be aware of this, because his brow knits into a frown, showing hesitation for the first time. Then he shrugs, sliding his hands up to wind around Shiro’s neck. “Just pull out, then.” He buries his nose in the crook of Shiro’s neck, inhaling deeply, _scenting_ him. _“Please_ , Shiro. Feels like ‘m burning up.”

Shiro closes his eyes briefly at the mental image of coming all over Keith’s stomach, then sliding his cock through the mess. “…Alright. Okay. Just –”

He doesn’t get to finish his sentence, because Keith’s mouth is already on his, going up on his toes and kissing him wet and dirty, moaning in the back of his throat. It’s borderline obscene, the way he licks into Shiro’s mouth like he’s trying to eat him alive, and Shiro just can’t help it any longer; he grips Keith’s jaw in one hand and kisses him back just as fiercely.

Keith’s practically trying to _climb_ him now, hips rutting against Shiro’s shallowly, and yeah, his eagerness is pretty hard to miss through those thin boxers. He hoists Keith up by the thighs and pushes him against the nearest wall for leverage.

“Need you to fuck me,” Keith pants against Shiro’s lips, fingers digging into his shoulders. “Been thinking about it for hours.”

Shiro grits his teeth, trying to hold it together even through Keith so obviously wants to take him apart. He slides one hand up to grab hold of Keith’s ass, and nearly drops him, because that underwear is _soaked_ through the back with slick. Shiro’s mouth waters, and he swallows hard. “Let’s move this to the bed.”

Keith makes a noise in the affirmative, but makes no move to disentangle his legs locked around Shiro’s hips, so they make their way across the room as a single, clumsy unit before Shiro tosses him down onto the mattress.

There’s something nearly feral in the way that Keith jolts back up and starts pulling at Shiro’s clothes without missing a beat; Shiro slows his hands just so he can get his vest and undershirt off without tearing them. Before he can even finish unzipping his pants, Keith makes quick work of what little clothing remains on his own body and flops back down onto the bed, watching Shiro with a piercing gaze.

Shiro drinks the sight in like a man dying of thirst, savoring every inch of bare skin, every plane of lithe muscle. Keith’s frame is wiry, but there’s something elegant in the line of his neck, the jut of his slim hips, the gentle curves of his thighs. Between them, his cock is stiff and leaking and flushed a dark, pretty pink. Shiro wants to take him in his mouth and suck him dry. Maybe later in Keith’s heat, when he isn’t aching so desperately to be fucked.

“Turn over,” Shiro instructs gruffly, then feels his face heat at the authority in his own voice. He’s never been one of _those_ alphas, and he doesn’t intend to start now. “Please,” he adds sheepishly, but Keith is already flipping over onto his belly and splaying his legs apart, ripping a full-body shudder out of Shiro.

He’s still so wet that it’s spreading down his inner thighs, which Shiro is glad for, because it abruptly occurs to him that Keith is likely still a virgin. He’d barely talked to anyone at the garrison besides Shiro, and after that, had apparently isolated himself in the middle of the desert for a year.  

“Shiro, c’mon,” Keith urges, and even though his dick is in strong agreement, Shiro kneels on the floor, spreads his cheeks apart, and bends his head forward.

“Fuck! _Fuck_!" Keith convulses so violently that Shiro has to hold his hips down. He’s only done this once before, but technique clearly isn’t an issue here, because Keith is whimpering, low and tortured-sounding in the back of his throat. He drags his tongue around the ring of muscle, then presses his lips to it in a perverse imitation of a kiss. Heat has rendered Keith’s hole slippery and pliant, but it’s still a tight fit to even wedge his tongue inside; Shiro hooks his thumbs over the rim and licks in, savoring every shudder, every delicious sound coaxed out of him.  

Without warning, Keith stiffens, then gasps out Shiro’s name, clenching down onto his tongue as he comes, hips jerking erratically. He goes limp, and Shiro reaches up a hand to smooth over the curve of his spine. Thankfully, the orgasm seems to have taken a bit of the edge off, and it’s not as difficult to ease one finger into Keith, then another. “Is this okay?” he confirms, just to be on the safe side.

“Mm. Mm-hmm,” Keith responds, muffled by mattress. He gives the impression of being sated, but Shiro knows better; they’ve only got a minute or so before Keith gets feverish and frantic again. He fits a third finger inside him and spreads them apart, watching with rapt attention as Keith’s hole twitches and lets out a trickle of fluid instinctively.

Shiro sits back on his heels and wipes his mouth with his clean, human hand. He needs to go ahead and do this before Keith starts to tense up. “How do you want to do this?” Shiro asks, resting a steadying hand on his upper thigh.

Keith props his head up on his arms and cranes his neck back to grin lazily at Shiro, face and neck flushed with arousal. “Just like this.”

It’s ridiculous; he’s fingered and eaten Keith out, but this is the thing that makes him blush. He gets to his feet, gives himself a few strokes – not that it needs it; he’s already so hard it hurts. Gripping the base, he traces his cock along Keith’s cleft, lets the blunt head catch against his hole.

“Take a deep breath,” Shiro advises.

Obediently, Keith’s back rises on an inhale, and Shiro presses in, slick easing the way to sink to the hilt in one smooth motion. He has to bite the inside of his cheek to distract himself; the sudden vicelike grip around his cock is both decadent and overwhelming. Keith’s breath hitches for a moment, then he lets out a loud, drawn-out whine.

Shiro presses down against him, chest to back, and covers a hand that’s twisted in the sheets, white-knuckled, with one of his own. “You okay, honey?”

He actually _feels_ the shiver run through Keith’s body. “It’s like I can feel you in my fuckin’ throat,” Keith rasps after a long pause that has Shiro’s stomach in knots. 

He’s about to ask if that’s a good thing or a bad thing when Keith rolls his hips up demandingly, almost knocking him off balance. The impulse to laugh bubbles up in his chest, but can’t quite make it out with the way that Keith feels around him, engulfing him in flame. 

In the rare, fleeting moments he’d allowed himself to fantasize about this, he’d always taken it slow, face-to-face with Keith, sliding into him like they had all the time in the world. But he’s not dreaming now, and Keith is face down, rutting back into his cock blindly, and Shiro – can’t.

Keith’s making these little breathy sounds every time Shiro pushes into him, like they’re being fucked out of him. That, Shiro’s own bitten off groans, and the crude wet squelch of his dick in Keith’s ass seem to echo in the quiet room. It feels like the inside of his head is buzzing.

The telltale flutter low in his stomach means that he’s not going to last much longer. He slides a hand under Keith to jerk him off, but he’s batted away. “Can’t,” Keith moans. “Not this early in heat, too sensitive.”

Shiro withdraws his hand, running it along Keith’s side. “Okay,” he murmurs soothingly.

Keith’s toes are starting to curl, muscles tensing. “Love you, Shiro, I love –” he babbles breathlessly, and then he’s coming around Shiro’s cock with a wordless cry.

Swallowing hard against the lump in his throat and holding Keith as he shakes apart, all Shiro can say is, “I got you.” Hopes that it’s enough for now.

He manages a few more thrusts before his knot starts to swell, pulling at Keith’s hole and making him whimper half-heartedly. He pulls out, jerks himself twice, and then he’s painting Keith’s back in spurts of pearly-white come. At once, his legs stagger under him, so he collapses on his back next to Keith with a flop, breathing heavily.

In the comfortable silence of sweat cooling on their bodies, Shiro lets his mind wander. They can’t run from this anymore. What that means for the two of them, he doesn’t know, and though he should be used to it by now, uncharted territory still manages to terrify him, just a little. But Keith’s heat has only just begun, so they have time to figure it out.

He really should go stock up on food and water.

Suddenly, there’s a banging at the wall, and a muffled, but still distinctive voice filters through. “ _Guys, not that that wasn’t a little hot, but_ some _of us don’t have sex buddies to work out our blue balls with. So maybe try keeping it down next time.”_

“Get earplugs,” Keith grouches back.

“Sorry, Lance,” Shiro responds with no small amount of embarrassment. Still – he can’t help a grin as he rolls over to kiss one of Keith’s red ears.

 

 

                                                                                                                                                          

**Author's Note:**

> PSA: lol PLEASE do not use the pulling out method if you are able to get pregnant it is not 100% effective. keith and shiro are terrible role models. also STDs don't exist b/c it's the future and there's like, vaccinations okay


End file.
